Cryptology ePrint Archive: Report 2006/450

Secure Cryptographic Workflow in the Standard Model

M. Barbosa and P. Farshim

Abstract: Following the work of Al-Riyami et al. we define the notion of key encapsulation mechanism supporting cryptographic workflow (WF-KEM) and prove a KEM-DEM composition theorem which extends the notion of hybrid encryption to cryptographic workflow. We then generically construct a WF-KEM from an identity-based encryption (IBE) scheme and a secret sharing scheme. Chosen ciphertext security is achieved using one-time signatures. Adding a public-key encryption scheme we are able to modify the construction to obtain escrow-freeness. We prove all our constructions secure in the standard model.

Category / Keywords: public-key cryptography / Cryptographic Workflow. Key Encapsulation. Secret Sharing. Identity-Based Encryption.

Publication Info: Indocrypt 2006

Date: received 28 Nov 2006

Contact author: farshim at cs bris ac uk

Available format(s): Postscript (PS) | Compressed Postscript (PS.GZ) | PDF | BibTeX Citation

Note: This is the full version of the paper.

Version: 20061204:102719 (All versions of this report)

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